The invention relates generally to lighting devices and related technologies. More particularly, this invention relates to a lighting device with a double sided light emitting diode (LED).
Conventional lighting devices use fluorescent tubes because fluorescent tubes emit light in a 360 degrees pattern from a central axis, and therefore it can emit light in all directions. For example, a traditional light box has multiple fluorescent tubes mounted at intervals in the box, and the fluorescent tubes illuminate every panel of the box.
Recently, more businesses and home owners are turning to LED tubes as their first choice for lighting, because LED tubes provide a variety of advantages over traditional fluorescent tubes, including but not limited to a lower long term cost, longer life expectancy, lower noise, warmer color, smaller environmental impact, and lower energy consumption.
As the viewing angle of an LED is less than 180 degrees from a central axis, double sided lighting LED tubes are used in the light box application. In some cases, the optic performance of LED light boxes may be not good enough. For example, there may be highly bright strip spot at the panel of a shallow LED light box. Furthermore, as the LEDs and electrical components generate heat during working and the LED tube typically is a completely enclosing area, it is difficult for the LED tube to expel the heat outside, which may reduce the lifetime of the LEDs and electrical components.